The purpose of this proposal is to demonstrate the capabilities of the University of Pittsburgh in continuing to participate in the Maternal-Fetal Medicine Units Network. Our Unit has been an active participant in the Network for the last nineteen years. During our tenure, which is the longest of all current or past MFMUs we have demonstrated our willingness to cooperate with other institutions and the NICHD in the development and implementation of clinical research protocols. We have been active participants in every aspect of Network activities. We have proposed protocols, have served on subcommittees of other protocols, have served on administrative subcommittees, have served as site visitors to evaluate other centers and have faithfully attended every one of the more than 80 Network meetings over the last nineteen years. We have effectively recruited patients and have provided intellectual input in the development of new projects as well as the implementation of protocols from our center and from others. The data provided by our unit have consistently been of the highest quality based on objective evaluation by the Data Coordinating Center. The Division of Maternal-Fetal Medicine is composed of 10 Maternal-Fetal Medicine specialists, four midwiyes, 6 research nurses, and three research associates who have committed in some way to the Network, either in the recruitment of patients, implementation of the studies at our site, patient evaluation, biological fluid collection, obtaining consent or development of protocols Eight research faculty in the Division are available to provide specialized expertise for Network projects. The obstetrical unit at the University of Pittsburgh is one of the largest private obstetrical service in the United States with over 8000 deliveries annually. In 2003, approximately 40% of our patients were considered as high risk prior to labor, Approximately 1800 women delivering at the University of Pittsburgh are indigent;1600 are black or Hispanic and 6500 are white, most of whom have third party insurance. The rates of smoking, obesity, drug abuse and hypertension at our center are among the highest in the Network. In previous trials the population at Magee proved unique. In both the low risk and high risk low dose aspirin studies, aspirin proved to be significantly better than placebo in preventing pre-eclampsia;ours was the only center where such a benefit was seen. These characteristics among our patients makes our institution particularly well suited for the performance of clinical trials and assures that results of Network studies are widely applicable across an entire spectrum of subjects. In this proposal we will: 1) describe our academic productivity and our contributions to the current Network, 2.) demonstrate the capabilities of our Unit, 3).provide evidence of our continuing commitment to the success of the Network of Maternal-Fetal Medicine Units and 4) propose a study for consideration by the Network. The relevance of the MFMU Network lies in its ability to perform relevant clinical research on pregnant women that could not otherwise be accomplished due to insufficient sample size. The Network has shown repeatedly that meaningful research can be performed with pregnant women and that that research can be undertaken safely.